U.S. patent number 9,472,110 [Application Number 14/095,037] was granted by the patent office on 2016-10-18 for aircraft taxi path guidance and display.
This patent grant is currently assigned to HONEYWELL INTERNATIONAL INC.. The grantee listed for this patent is HONEYWELL INTERNATIONAL INC.. Invention is credited to Rocco DiVito, Muthukumar Murthy, Alpana Priyamvada.
United States Patent |
9,472,110 |
Murthy , et al. |
October 18, 2016 |
Aircraft taxi path guidance and display
Abstract
An aircraft taxi path guidance and display system is provided.
The aircraft taxi path guidance and display system includes or
cooperates with at least one source of aircraft status data, and a
source of airport feature data associated with an airport field.
The aircraft taxi path guidance and display system includes a
processor operationally coupled to the source of aircraft status
data and to the source of airport feature data. In response to
aircraft status data and airport feature data, the processor
predicts undesired deviations from an active surface area (e.g., an
excursion). The processor generates corrective action associated
with the excursion, and displays symbology that is graphically
representative of the corrective action.
Inventors: |
Murthy; Muthukumar (Tamilnadu,
IN), Priyamvada; Alpana (Karnataka, IN),
DiVito; Rocco (Etobicoke, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
HONEYWELL INTERNATIONAL INC. |
Morristown |
NJ |
US |
|
|
Assignee: |
HONEYWELL INTERNATIONAL INC.
(Morris Plains, NJ)
|
Family
ID: |
51868853 |
Appl.
No.: |
14/095,037 |
Filed: |
December 3, 2013 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20150154874 A1 |
Jun 4, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G08G
5/0021 (20130101); G08G 5/06 (20130101); G08G
5/065 (20130101) |
Current International
Class: |
G08G
5/06 (20060101); G08G 5/00 (20060101) |
Field of
Search: |
;701/3,5,9,14,15,16,528 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1842772 |
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May 2009 |
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EP |
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2211324 |
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Jul 2010 |
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EP |
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2610590 |
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Jul 2013 |
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EP |
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Other References
EP Extended Search Report for EP 14192173.4-1803 dated Apr. 15,
2015. cited by applicant .
EP Examination Report for EP 14192173.3-1803 dated Jun. 5, 2016.
cited by applicant.
|
Primary Examiner: Holwerda; Stephen
Attorney, Agent or Firm: Lorenz & Kopf, LLP
Claims
What is claimed is:
1. A method for displaying aircraft taxi path guidance on a display
unit in an aircraft, the method comprising: obtaining aircraft
status data comprising heading data, steering angle and
differential speed of the main landing gear; obtaining airport
feature data; processing, by a processor, the aircraft status data
and the airport feature data to (i) generate a trend line that
represents an aircraft predicted taxi path, and (ii) wherein a
surface area within the airport in which the aircraft may safely
travel comprises an airport active surface area, predict an
excursion when an intersection of the aircraft predicted taxi path
with a shoulder of an airport active surface area occurs within a
predetermined distance threshold; in response to predicting the
excursion, generating, corrective action associated with the
excursion, wherein the corrective action is based on the
differential speed of the main landing gear; and displaying, on the
display unit, symbology that is graphically representative of (i)
the trend line, and (ii) the corrective action.
2. A method according to claim 1, further comprising monitoring the
trend line with respect to a centerline of the airport active
surface area.
3. A method according to claim 1, wherein the predetermined
distance threshold is based on: airport active surface area
dimensions, aircraft speed, aircraft weight, and aircraft center of
gravity.
4. A method according to claim 1, further comprising determining a
maximum steering setting of the aircraft.
5. A method according to claim 1, wherein the step of displaying
further comprises: rendering at least one textual warning
associated with the excursion.
6. A method according to claim 5, wherein the at least one textual
warning comprises at least one of: a steering command, a speed
command, a breaking command, and an abort command.
7. A method according to claim 1, wherein the step of generating
includes emitting an audible alert.
8. A method according to claim 1, wherein aircraft status data
comprises at least one of: aircraft length, aircraft wing width,
aircraft turning radius, aircraft speed, aircraft present position,
aircraft steering angle, differential speed of main landing gear,
and aircraft heading.
9. A method according to claim 1, wherein the step of generating is
based on at least one of: width of active surface area, aircraft
length, aircraft wing width, aircraft turning radius, and aircraft
speed.
10. A method according to claim 1, wherein displaying the trend
line further comprises rendering the trend line in a visually
distinguishable or highlighted manner when an intersection of the
aircraft predicted taxi path with a shoulder of an airport active
surface area is predicted by the processor to occur within a
predetermined distance threshold.
11. A method for displaying aircraft taxi path guidance for an
aircraft, the method comprising: obtaining aircraft status data
comprising heading data, steering angle and differential speed of
main landing gear; obtaining airport feature data; determining,
based on at least the aircraft status data and airport feature
data, a trend line that represents an aircraft predicted taxi path
of the aircraft; wherein a surface area within the airport in which
the aircraft may safely travel comprises an airport active surface
area, determining if the aircraft predicted taxi path enters a
shoulder of an airport active surface area within a predetermined
distance threshold; generating corrective action associated with an
excursion when it is determined that the aircraft predicted taxi
path enters the shoulder of the airport active surface area within
the predetermined distance threshold, wherein the corrective action
is based on the differential speed of the main landing gear; and
displaying, on a display unit, symbology that is graphically
representative of the corrective action and symbology graphically
representative of the aircraft predicted taxi path.
12. A method according to claim 11, wherein the predetermined
distance threshold is based on at least one of: active surface area
dimensions, aircraft speed, aircraft weight and aircraft center of
gravity.
13. A method according to claim 11, wherein the step of generating
further comprises determining a maximum steering setting of the
aircraft.
14. A method according to claim 11, wherein the aircraft predicted
taxi path is a displayed in a visually distinguishable color when
it is determined that the aircraft predicted taxi path enters a
shoulder of the airport active surface area within a predetermined
distance threshold.
15. A system for displaying aircraft taxi path guidance and
display, the system comprising: a first source of aircraft status
data comprising heading data, steering angle and differential speed
of main landing gear; a second source of airport feature data; a
display unit; and a processor operationally coupled to the first
source, the second source, and the display unit, the processor
configured to: (a) receive the aircraft status data; (b) receive
the airport feature data; (c) define a surface area within the
airport in which the aircraft may safely travel as an airport
active surface area; (d) determine, in response to at least the
aircraft status data and airport feature data, an aircraft position
with respect to an active surface area; (e) generate, in response
to at least the aircraft status data and airport feature data, a
trend line that represents an aircraft predicted taxi path; and (f)
predict an excursion when an intersection of the aircraft predicted
taxi path with a shoulder of the airport active surface area occurs
within a predetermined distance threshold; and, when an excursion
is predicted, (i) generate corrective action associated with the
excursion, wherein the corrective action is based on the
differential speed of the main landing gear, (ii) generate
symbology on the display unit that is graphically representative of
the corrective action and graphically representative of the trend
line, and (iii) generate an audible alert.
16. A system according to claim 15, wherein the processor is
further configured to determine a maximum steering setting of the
aircraft.
Description
TECHNICAL FIELD
Embodiments of the subject matter described herein relate generally
to avionics guidance and display systems. More specifically,
embodiments of the subject matter relate to aircraft taxi path
guidance and display systems that display corrective action alerts
when a deviation from an airport active surface area is
predicted.
BACKGROUND
In its simplest form, an aircraft may be guided along a taxi path
by a crew member manually steering the aircraft using a flight deck
controller (e.g. a tiller) while looking out a window. In this
case, the crew member utilizes their best judgment regarding how to
guide the aircraft along an acceptable taxi path. Various visual
guidance systems have been utilized to improve upon manual
steering. Visual guidance systems generally determine a taxi path
based on supplied inputs such as air traffic control (ATC)
clearance, and present instructions for guiding the aircraft along
the suggested taxi path; e.g. speed, steering, when to turn thrust
engines off and when to turn electric drive motors on, etc. ATC
clearance input can include taxi route, assigned take-off or
landing runway, hold points, etc.
An aircraft may be powered during the taxi by a traditional taxi
system or by an electric taxi system (ETS). Traditional aircraft
taxi systems utilize the primary thrust engines (running at idle
speed) and the braking system of the aircraft to regulate the speed
of the aircraft during taxi. The electric taxi system (ETS) is an
efficient upgrade to the traditional taxi system for aircraft.
Electric taxi systems have traction drive systems that employ
electric motors that can be powered by an auxiliary power unit
(APU), rather than the primary thrust engines. Aircraft equipped
with ETS have the ability to autonomously push back from the
terminal, and are therefore not reliant upon the conventionally
used pushback tractors, or tugs. Further, the ETS can provide most
of the basic functions of tugs, and can serve as the main engine
for taxiing
The ETS also provides expanded turning capability. Traditional
steering is performed by the aircraft nose wheel, and the radius of
turn achieved is affected by aircraft size and wing length
(generally approximately 60 degrees). In contrast, the ETS can
control the main landing gear (MLG) relative speed between left and
right wheels, resulting in sharper turns than what can be achieved
by traditional steering (approximately 60-90 degrees). The ETS
supported turns are referred to as "tight turns" or tight turn
operations. All of the aforementioned advantages provided by ETS
are autonomous.
During various aircraft ground operations such as a taxi, a tight
turn, or a reverse operation, a deviation from an airport active
surface area may occur. Traditionally, tools such as moving maps on
Heads Down Displays, Heads Up Displays, Surface Guidance Systems,
Enhanced Vision Systems, and the like, have been utilized to
minimize the likelihood of occurrence of such a deviation. However,
what is lacking is a tool to display an alert, such as an audible
alert, a warning text, or a graphical representation of corrective
action, when a deviation from the airport active surface area is
predicted.
Accordingly, an aircraft taxi path guidance and display system that
graphically displays an alert and corrective action when a
deviation from the airport active surface area is predicted is
desirable. It is desirable for the system to also display the
alerts and corrective action for tight turn and reverse operations.
Such an aircraft taxi path guidance and display system would
increase situational awareness by proactively alerting the crew to
avert predicted deviations.
Other desirable features will become apparent from the following
detailed description and the appended claims, taken in conjunction
with the accompanying drawings and this background.
BRIEF SUMMARY
A method for displaying aircraft taxi path guidance is provided.
The method comprises obtaining aircraft status data for the
aircraft and obtaining airport feature data associated with an
airport field. In response to at least the aircraft status data and
airport feature data, corrective action associated with an
excursion is generated, wherein an excursion is a deviation from an
airport active surface area. Symbology that is graphically
representative of the corrective action is displayed.
Also provided is a method for displaying aircraft taxi path
guidance. The method comprises obtaining aircraft status data and
airport feature data. In response to at least the aircraft status
data and airport feature data, the method determines an aircraft
position relative to a centerline of an active surface area. Based
on at least the aircraft position, the method generates corrective
action associated with an excursion. Symbology that is graphically
representative of the corrective action is displayed. Additionally,
symbology that is graphically representative of the predicted
aircraft taxi path is displayed.
A system for displaying taxi path guidance is also provided. The
system includes a first source of aircraft status data, a second
source of airport feature data, a display unit, and a processor
operationally coupled to the first source, the second sources and
the display unit. The processor is configured to receive the
aircraft status data and the airport feature data. In response to
at least the aircraft status data and airport feature data, the
processor is configured to determine an aircraft position with
respect to an active surface area. Based, at least in part on the
aircraft position, the processor generates corrective action
associated with an excursion. The processor further generates
symbology that is graphically representative of the corrective
action on the display unit.
This summary is provided to introduce a selection of concepts in a
simplified form that are further described below in the detailed
description. This summary is not intended to identify key features
or essential features of the claimed subject matter, nor is it
intended to be used as an aid in determining the scope of the
claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the subject matter may be derived
by referring to the detailed description and claims when considered
in conjunction with the following figures, wherein like reference
numbers refer to similar elements throughout the figures and
wherein:
FIG. 1 is a simplified schematic representation of an aircraft
having an aircraft taxi path display system;
FIG. 2 is a block diagram of an exemplary embodiment of an aircraft
taxi path guidance and display system suitable for use with an
aircraft;
FIG. 3 is a flow chart that illustrates an exemplary embodiment of
the prediction process utilized in the aircraft taxi path guidance
and display process;
FIG. 4 is a graphical representation of a 2D-Airport Moving Map
having rendered thereon an airport field, a predicted excursion,
and corrective action;
FIG. 5 is a graphical representation of a synthetic vision system
display having rendered thereon an airport field, a predicted
excursion, and corrective action;
FIG. 6 is a graphical representation of a synthetic vision system
display having rendered thereon an airport field, a predicted
excursion in a reverse operation, and corrective action;
FIG. 7 is a graphical representation of a synthetic vision system
display having rendered thereon an airport field, a predicted
excursion in a turn operation, where corrective action is to
increase steering during the turn; and
FIG. 8 is a graphical representation of a synthetic vision system
display having rendered thereon an airport field, a predicted
excursion in a tight turn operation, where corrective action is to
abort the turn.
DETAILED DESCRIPTION
The following detailed description is merely illustrative in nature
and is not intended to limit the embodiments of the subject matter
or the application and uses of such embodiments. As used herein,
the word "exemplary" means "serving as an example, instance, or
illustration." Any implementation described herein as exemplary is
not necessarily to be construed as preferred or advantageous over
other implementations. Furthermore, there is no intention to be
bound by any expressed or implied theory presented in the preceding
technical field, background, brief summary, or the following
detailed description.
Techniques and technologies may be described herein in terms of
functional and/or logical block components and with reference to
symbolic representations of operations, processing tasks, and
functions that may be performed by various computing components or
devices. Such operations, tasks, and functions are sometimes
referred to as being computer-executed, computerized,
software-implemented, or computer-implemented. It should be
appreciated that the various block components shown in the figures
may be realized by any number of hardware, software, and/or
firmware components configured to perform the specified functions.
For example, an embodiment of a system or components may employ
various integrated circuit components (e.g. memory elements,
digital signal processing elements, logic elements, look-up tables,
or the like) that may carry out a variety of functions under the
control of one or more microprocessors or other control
devices.
The system and methods described herein can be deployed with any
vehicle that may be subjected to taxi operations, such as aircraft.
Aircraft taxi operations are sometimes referred to as an aircraft
rolling phase or ground traffic flow. The exemplary embodiment
described herein assumes that the aircraft includes an electric
taxi system (ETS), which utilizes one or more electric motors as a
traction system to drive the wheels of the aircraft during taxi
operations. The ETS is capable of controlling the aircraft on all
aircraft taxi operations. The surface area within the airport in
which the aircraft may safely travel is referred to as airport
active surface area, and includes, but is not limited to, runway
paths and taxi paths. Any inappropriate exit or deviation from the
airport active surface area is referred to as an excursion. An
excursion may occur during various aircraft maneuvers (e.g., a taxi
operation, a tight turn, or a reverse operation).
The system and methods presented herein display a warning with
corrective action in response to a predicted excursion. The warning
alerts the aircraft crew via a display of corrective action. The
corrective action may then be utilized to optimize and otherwise
enhance safety during taxi operations. The corrective action may be
based on one or more factors such as, without limitation: aircraft
position, aircraft speed, aircraft turning radius, aircraft wing
width, and the differential speed of the main landing gear. In
certain embodiments, the corrective action is rendered with a
graphical display of the airport field to provide visual guidance.
In various embodiments, the graphical representation of the
corrective action may include an alert in the form of symbols
and/or text. The corrective action may be displayed using database
assembled images such as 2D-Airport Moving Map, Synthetic Vision
system, Surface Guidance System, Enhanced Guidance System, or the
like. The display system may be implemented as an onboard flight
deck system, as a portable computer, as an electronic flight bag,
or any combination thereof. The Runway Awareness and Advisory
System (RAAS) may be utilized to provide supplemental information
on position of the aircraft relative to the runway. Some
embodiments include corrective action guidance in the form of
audible warnings.
FIG. 1 is a simplified schematic representation of an aircraft (AC)
100. For the sake of clarity and brevity, FIG. 1 does not depict
the vast number of systems and subsystems that would appear onboard
a practical implementation of the aircraft 100. Instead, FIG. 1
merely depicts some of the notable functional elements and
components of the aircraft 100 that support the various features,
functions, and operations described in more detail below. In this
regard, the aircraft 100 may include, without limitation: a cockpit
display 101, a processor architecture 102; at least two primary
thrust engines 104; an engine-based taxi system 106; a fuel supply
108; an auxiliary power unit (APU) 110; an electric taxi system
112; and a brake system 114. These elements, components, and
systems may be coupled together as needed to support their
cooperative functionality.
The processor architecture 102 may be implemented or realized with
at least one general purpose processor, a content addressable
memory, a digital signal processor, an application specific
integrated circuit, a field programmable gate array, any suitable
programmable logic device, discrete gate or transistor logic,
discrete hardware components, or any combination designed to
perform the functions described herein. A processor device may be
realized as a microprocessor, a controller, a microcontroller, or a
state machine. Moreover, a processor device may be implemented as a
combination of computing devices, e.g., a combination of a digital
signal processor and a microprocessor, a plurality of
microprocessors, one or more microprocessors in conjunction with a
digital signal processor core, or any other such configuration. As
described in more detail below, the processor architecture 102 is
configured to support various electric taxi path guidance
processes, operations, and display functions.
In practice, the processor architecture 102 may be realized as an
onboard component of the aircraft 100 (e.g., a flight deck control
system, a flight management system, or the like), or it may be
realized in a portable computing device that is carried onboard the
aircraft 100. For example, the processor architecture 102 could be
realized as the central processing unit (CPU) of a laptop computer,
a tablet computer, or a handheld device. As another example, the
processor architecture 102 could be implemented as the CPU of an
electronic flight bag carried by a member of the flight crew or
mounted permanently in the aircraft. Electronic flight bags and
their operation are explained in documentation available from the
United States Federal Aviation Administration (FAA), such as FAA
document AC 120-76A.
The processor architecture 102 may include or cooperate with an
appropriate amount of memory (not shown), which can be realized as
RAM memory, flash memory, EPROM memory, EEPROM memory, registers, a
hard disk, a removable disk, a CD-ROM, or any other form of storage
medium known in the art. In this regard, the memory can be coupled
to the processor architecture 102 such that the processor
architecture 102 can read information from, and write information
to, the memory. In the alternative, the memory may be integral to
the processor architecture 102. In practice, a functional or
logical module/component of the system described here might be
realized using program code that is maintained in the memory.
Moreover, the memory can be used to store data utilized to support
the operation of the system, as will become apparent from the
following description.
The illustrated embodiment of the aircraft includes at least two
primary thrust engines 104, which may be fed by the fuel supply
108. The engines 104 serve as the primary sources of thrust during
flight. The engines 104 may also function to provide a relatively
low amount of thrust (e.g., at idle) to support a conventional
engine-based taxi system 106. When running at idle, the engines 104
typically provide a fixed amount of thrust to propel the aircraft
100 for taxi maneuvers. When the engines 104 are utilized for taxi
operations, the speed of the aircraft is regulated by the brake
system 114.
Exemplary embodiments of the aircraft 100 also include the electric
taxi system 112 (which may be in addition to or in lieu of the
engine-based taxi system 106 that typically provides a pilot with
manual control of the aircraft). In certain implementations, the
electric taxi system 112 includes at least one electric motor (not
shown in FIG. 1) that serves as the traction system for the drive
wheel assemblies (not shown in FIG. 1) of the aircraft 100. The
electric motor may be powered by the APU 110 onboard the aircraft
100, which in turn is fed by the fuel supply 108. As described in
more detail below, the electric taxi system 112 can be controlled
by a member of the flight crew to achieve a desired taxi speed.
Unlike the conventional engine-based taxi system 106, the electric
taxi system 112 can be controlled to regulate the speed of the
drive wheels without requiring constant or frequent actuation of
the brake system 114. This advantage provided by ETS allows for
tighter turning ratios. The aircraft 100 may employ any suitably
configured electric taxi system 112, which employs electric motors
to power the wheels of the aircraft during taxi operations.
FIG. 2 is a schematic representation of an exemplary embodiment of
a taxi path guidance and display system 200 suitable for use with
the aircraft 100. Depending upon the particular embodiment, the
taxi path guidance and display system 200 may be realized in
conjunction with a ground management system 202, which in turn may
be implemented in a line replaceable unit (LRU) for the aircraft
100, in an onboard subsystem such as the flight deck display
system, in an electronic flight bag, in an integrated modular
avionics (IMA) system, or the like. The illustrated embodiment of
the taxi path guidance and display system 200 generally includes,
without limitation: a path guidance module 204; an engine
start/stop guidance module 206; an electric taxi speed guidance
module 208; a path prediction module 210; a symbology generation
module 212; and a display system 214. The taxi path guidance and
display system 200 may also include or cooperate with one or more
of the following elements, systems, components, or modules:
databases 216; a controller 218 for the electric taxi system motor;
braking system 219, and sensor data sources 220. In practice,
various functional or logical modules of the taxi path guidance and
display system 200 may be implemented with the processor
architecture 102 (and associated memory) described above with
reference to FIG. 1. The taxi path guidance and display system 200
may employ any appropriate communication architecture, such as
datalink subsystem 222, or any arrangement that facilitates
inter-function data communication, transmission of control and
command signals, provision of operating power, transmission of
sensor signals, etc.
The taxi path guidance and display system 200 is suitably
configured such that the path guidance module 204, the engine
start/stop guidance module 206, and/or the electric taxi speed
guidance module 208 are responsive to or are otherwise influenced
by a variety of inputs. For this particular embodiment, the
influencing inputs are obtained from one or more of the sources and
components listed above (i.e., the items depicted at the left side
of FIG. 2). The outputs of the path guidance module 204, the engine
start/stop guidance module 206, and/or the electric taxi speed
guidance module 208 are provided to the symbology generation module
212, which generates corresponding graphical representations
suitable for rendering with a graphical display of an airport
field. The symbology generation module 212 cooperates with the
display system 214 to present taxi path guidance information to the
user.
The databases 216 represent sources of data and information that
may be used to generate taxi path guidance information. For example
the databases 216 may store any of the following, without
limitation: airport location data; airport feature data, which may
include layout data, coordinate data, data related to the location
and orientation of gates, runways, taxiways, etc.; airport
restriction or limitation data; aircraft configuration data;
aircraft model information; engine cool down parameters, such as
cool down time period; engine warm up parameters, such as warm up
time period; electric taxi system specifications; and the like. In
certain embodiments, the databases 216 store airport feature data
that is associated with (or can be used to generate) database
assembled images, such as a 2D-Airport Moving Map or synthetic
graphical representations of a departure or destination airport
field. The databases 216 may be updated as needed to reflect the
specific aircraft, the current flight path, the departing and
destination airports, and the like.
The controller 218 includes the control logic and hardware for the
electric taxi motor. In this regard, the controller 218 may include
one or more user interface elements that enable the pilot to
activate, deactivate, and regulate the operation of the electric
taxi system as needed. The controller 218 may also be configured to
provide information related to the status of the electric taxi
system, such as operating condition, wheel speed, motor speed, and
the like.
The sensor data sources 220 represent various sensor elements,
detectors, diagnostic components, and their associated subsystems
onboard the aircraft. In this regard, the sensor data sources 220
function as sources of aircraft status data for the host aircraft.
In practice, the taxi path guidance and display system 200 could
consider any type or amount of aircraft status data including,
without limitation, data indicative of: tire pressure; nose wheel
angle; brake temperature; brake system status; outside temperature;
ground temperature; engine thrust status; primary engine on/off
status; aircraft ground speed; geographic position of the aircraft;
wheel speed; electric taxi motor speed; electric taxi motor on/off
status; or the like.
The datalink subsystem 222 is utilized to provide air traffic
control data to the host aircraft, preferably in compliance with
known standards and specifications. Using the datalink subsystem
222, the taxi path guidance and display system 200 can receive air
traffic control data from ground based air traffic controller
stations and equipment. In turn, the taxi path guidance and display
system 200 can utilize such air traffic control data as needed. For
example, taxi maneuver clearance and other airport navigation
instructions may be provided by an air traffic controller using the
datalink subsystem 222.
The path guidance module 204, the engine start/stop guidance module
206, and the electric taxi speed guidance module 208 are suitably
configured to respond in a dynamic manner to provide real-time
guidance for optimized operation of the electric taxi system. In
practice, the taxi path guidance information (e.g., taxi path
guidance information, start/stop guidance information for the
engines, and speed guidance information for the electric taxi
system) might be generated in accordance with a fuel conservation
specification or guideline for the aircraft, in accordance with an
operating life longevity specification or guideline for the brake
system 114 (see FIG. 1), and/or in accordance with other
optimization factors or parameters. The path guidance module 204
continually processes relevant input data and, in response thereto,
generates taxi path guidance information related to a desired taxi
route to follow. The desired taxi route can then be presented to
the flight crew in an appropriate manner. The engine start/stop
guidance module 206 processes relevant input data and, in response
thereto, generates start/stop guidance information that is
associated with operation of the primary thrust engine(s) and/or is
associated with operation of the electric taxi system. As explained
in more detail below, the start/stop guidance information may be
presented to the user in the form of symbology or textual
indicators in a graphical representation of the airport field. The
electric taxi speed guidance module 208 processes relevant input
data and, in response thereto, generates speed guidance information
for the onboard electric taxi system. The speed guidance
information may be presented to the user as a dynamic alphanumeric
field displayed in the graphical representation of the airport
field.
In the embodiments presented herein, the path guidance module 204
is coupled to and communicates with a path prediction module 210.
The path prediction module 210 relies on input data such as, but
not limited to, the required airport feature data and the status
and sensor data associated with the current aircraft. Based in part
on the input data, the path prediction module 210 calculates
aircraft heading and generates a trend line that represents the
aircraft predicted taxi path. Aircraft heading is based upon, inter
alia, the nose wheel steering angle, and main landing differential
steering commands. The path prediction module 210 monitors the taxi
path trend line with respect to the centerline of the relevant
active surface area of the airport. The path prediction module 210
determines the deviation between the taxi path trend line and the
centerline. When the taxi path trend line indicates an impending
intersection of the aircraft taxi path with a shoulder of a
relevant active area, the distance threshold is checked. An
intersection of the taxi path trend line and shoulder at or below
the distance threshold is referred to as an excursion. The distance
threshold is a predetermined distance based on one or more factors
such as, but not limited to: aircraft length, wing width, width of
active surface area, aircraft speed, and aircraft turning angle.
When an excursion is predicted, the maximum steering capacity is
checked, and a corresponding alert is generated. In response to the
alert, the path guidance module 204 prompts the symbology
generation module 212 to generate corrective action for display on
the display system 214.
The symbology generation module 212 can be suitably configured to
receive the output of the path guidance module 204, the engine
start/stop guidance module 206, and the electric taxi speed
guidance module 208, and to process the received information in an
appropriate manner for incorporation, blending, and integration
with the dynamic graphical representation of the airport field.
Thus, the electric taxi path guidance information can be merged
into the graphical display to provide enhanced situational
awareness and taxi instructions to the pilot in real-time.
The exemplary embodiment described herein relies on graphically
displayed and rendered taxi path guidance information. Accordingly,
the display system 214 includes at least one display element. In an
exemplary embodiment, the display element cooperates with a
suitably configured graphics system (not shown), which may include
the symbology generation module 212 as a component thereof. This
allows the display system 214 to display, render, or otherwise
convey one or more graphical representations, synthetic displays,
graphical icons, visual symbology, or images associated with
operation of the host aircraft on the display element, as described
in greater detail below. In practice, the display element receives
image rendering display commands from the display system 214 and,
in response to those commands, renders a dynamic graphical
representation of the airport field during taxi operations.
In an exemplary embodiment, the display element is realized as an
electronic display configured to graphically display flight
information or other data associated with operation of the host
aircraft 100 under control of the display system 214. The display
system 214 is usually located within a cockpit of the host aircraft
100. Alternatively (or additionally), the display system 214 could
be realized in a portable computer, and electronic flight bag, or
the like.
Although the exemplary embodiment described herein presents the
taxi path guidance and display information in a graphical
(displayed) manner, the guidance information could alternatively or
additionally be annunciated in an audible manner. For example, in
lieu of graphics, the system could provide audible steering
instructions (e.g., steer left, steer right, etc.) and/or braking
instructions. Alternatively, the system may utilize indicator
lights or other types of feedback instead of a graphical display of
the airport field.
FIG. 3 is a flow chart that illustrates an exemplary embodiment of
a prediction process 300, carried out by path prediction module 210
(FIG. 2). The process 300 may be performed by an appropriate system
or component of the host aircraft 100, such as the taxi path
guidance and display system 200. The various tasks performed in
connection with the process 300 may be performed by software,
hardware, firmware, or any combination thereof. For illustrative
purposes, the following description of the process 300 may refer to
elements mentioned above in connection with FIG. 1 and FIG. 2. In
practice, portions of the process 300 may be performed by different
elements of the described system, e.g., the processor architecture
102, the ground management system 202, the path guidance module
204, the symbology generation module 212, or the display system
214. It should be appreciated that the process 300 may include any
number of additional or alternative steps, the steps shown in FIG.
3 need not be performed in the illustrated order, and process 300
may be incorporated into a more comprehensive procedure or process
having additional functionality not described in detail herein.
Moreover, one or more of the steps shown in FIG. 3 could be omitted
from an embodiment of the process 300 as long as the intended
overall functionality remains intact.
Process 300 is performed before the aircraft takes off or after it
has landed. More specifically, the process 300 can be performed
while the aircraft is in a ground operation, such as a taxi, and in
a virtually continuous manner at a relatively high refresh
rate.
The process 300 obtains, receives, accesses, or acquires certain
data and information that influences the generation and
presentation of taxi path guidance and display information. In this
regard, the process may acquire input data from various data
sources and databases. The input data may also include data
received from air traffic control via the datalink subsystem 222.
Referring again to FIG. 2, the various elements, systems, and
components that feed the taxi path guidance and display system 200
may provide the input data for STEPS 302, 304 and 308.
In the exemplary embodiment, the prediction process 300 accesses or
retrieves aircraft position data from a navigation or Global
Positioning System (STEP 302). Status data for the host aircraft
"AC" (such as heading data, steering angle, differential speed,
weight, center of gravity "CG," etc.) and from data sources such as
onboard sensors and detectors is retrieved (STEP 304). Based on the
aircraft position and status data the process computes and displays
a predicted aircraft taxi path trend line on a display unit (STEP
306).
Next, process 300 retrieves the airport feature data that is
associated or otherwise indicative of graphical representations of
the particular airport field. The airport feature data might be
maintained onboard the aircraft, and the airport feature data
corresponds to, represents, or is indicative of certain visible and
displayable features of the airport field of interest. The airport
feature data includes a taxi map with an identified active surface
area for the airport taxi operation.
The taxi map is compared to the aircraft position (STEP 308). The
aircraft position is compared to the center line of the identified
active surface area (STEP 310), and any offset from the center line
is computed (STEP 312). Next, the process checks whether the
aircraft taxi path trend line indicates travel onto the shoulder of
the identified active surface area at or below a distance threshold
(STEP 314). The distance threshold in STEP 314 is based on factors
such as, but not limited to, active surface dimensions, aircraft
speed, size, wing width and weight. If the taxi path trend line
indicates travel onto the shoulder within the distance threshold
(STEP 314), the process next checks the aircraft maximum steering
setting (STEP 316). If the aircraft's maximum steering setting has
been reached, the process displays an alert with an abort message
and/or audible warning (STEP 320). In the alternative, if steering
is determined to be a viable corrective action, the process
displays an alert recommending corrective action and/or an audible
alert is generated (STEP 318). The process then returns to reading
aircraft position data (STEP 302).
Although the corrective action could be conveyed, presented, or
annunciated to the flight crew or pilot in different ways, the
exemplary embodiment described herein displays graphical
representations of the corrective action in addition to the taxi
path guidance information, the engine start/stop guidance
information, and the speed guidance information. More specifically,
the process 300 renders corrective action information with a
dynamic graphical display of the airport field. Audible warnings
may be included. In this example, STEP 318 and STEP 320 render the
corrective action within a graphical display of the airport field
in accordance with variables such as the current geographic
position data of the host aircraft, the current heading data of the
host aircraft, and the airport feature data. As explained in more
detail below, the graphical representation of the airport field
might include graphical features corresponding to airport active
surface areas such as taxiways, runways, taxiway/runway signage,
the desired taxi path, and the like. The graphical display may also
include graphical representations of an engine on/off indicator and
a target electric taxi speed indicator, and various textual
commands. In practice, the dynamic graphical display may also
include a perspective view of terrain near or on the airport field.
In certain embodiments, the image rendering display commands may
also be used to control the rendering of additional graphical
features, such as flight instrumentation symbology, flight data
symbology, and the like.
The relatively high refresh rate of the process 300 results in a
relatively seamless and immediate updating of the display. Thus,
the process 300 is iteratively repeated to update the graphical
representation of the airport field and its features, possibly
along with the corrective action and other graphical elements of
the synthetic display. Notably, the taxi path display information
may also be updated in an ongoing manner to reflect changes to the
operating conditions, traffic conditions, air traffic control
instructions, and the like. In practice, the process 300 can be
repeated indefinitely and at any practical rate to support
continuous and dynamic updating and refreshing of the display in
real-time or virtually real-time. Frequent updating of the displays
enables the flight crew to obtain and respond to the current
operating situation in virtually real-time, enhancing situational
awareness.
FIG. 4 is a graphical representation of a top-down display 400
having rendered thereon a 2D-Airport Moving Map of an airport field
402 and aircraft 100. The display 400 includes a graphical
representation of a taxi path 403, which corresponds to the taxiway
on which the host aircraft 100 is currently traveling in a ground
operation. Graphical representations of various other features,
structures, fixtures, and/or elements associated with the airport
field 402 are included in display 400; such as other taxiways 405,
conformally rendered in accordance with their real-world
counterpart taxiways. Display 400 also includes a trend line 404
depicting the predicted aircraft taxi path. Symbology indicative of
corrective action to be taken is shown at 406.
FIG. 4 depicts a moment in time when the aircraft 100 is being
driven by the electric taxi system, and trend line 404 shows the
predicted aircraft path. In display 400, trend line 404 indicates a
predicted excursion, in which aircraft 100 travels away from the
centerline of the taxi path to the right, crosses onto the shoulder
within an unsafe distance, and continues to travel off of taxi path
403 to the right. The guidance and display system may generate an
audible alert in response to the predicted excursion. In response
to the predicted excursion, the guidance and display system
graphically displays an alert. The graphical display of the alert
may comprise one or more symbolic representations, such as: the
trend line 404 rendered in a visually distinguishable or
highlighted manner that is easy to detect and recognize; text and
symbols 406 conveying corrective action to avert the excursion,
rendered in a visually distinguishable or highlighted manner;
etc.
FIG. 5 is a graphical representation of a display 500 having
rendered thereon a synthetic vision system map of an airport field
502 and aircraft 100. The display 500 includes a graphical
representation of a taxi path
503, which corresponds to the taxiway on which the host aircraft
100 is currently traveling in a ground operation. Graphical
representations of various other features, structures, fixtures,
and/or elements associated with the airport field 502 are included
in display 500; such as other taxiways 508, 510, conformally
rendered in accordance with their real-world counterpart taxiways.
Display 500 also includes a trend line 504 depicting the predicted
aircraft taxi path. Symbology indicative of corrective action to be
taken is shown at 506.
FIG. 5 depicts a moment in time when the aircraft 100 is being
driven by the electric taxi system, and trend line 504 shows the
predicted aircraft path. In display 500, trend line 504 indicates a
predicted excursion, in which aircraft 100 travels away from the
centerline of the taxi path to the right, crosses onto the shoulder
within an unsafe distance, and continues to travel off taxi path
503 to the right. The guidance and display system may generate an
audible alert in response to the predicted excursion. In response
to the predicted excursion, the guidance and display system
graphically displays an alert. The graphical display of the alert
may comprise one or more symbolic representations, such as: the
trend line 504 rendered in a visually distinguishable or
highlighted manner that is easy to detect and recognize; text and
symbols 506 conveying corrective action to avert the excursion,
rendered in a visually distinguishable or highlighted manner;
etc.
FIG. 6 is a display 600 having rendered thereon a synthetic vision
system map of an airport field 602 and aircraft 100. The display
600 includes a graphical representation of a taxi path 603, which
corresponds to the taxiway on which the host aircraft 100 is
currently traveling in a ground operation. Graphical
representations of various other features, structures, fixtures,
and/or elements associated with the airport field 602 are included
in display 600; such as other taxiways 608, conformally rendered in
accordance with their real-world counterpart taxiways. Display 600
also includes a trend line 604 depicting the predicted aircraft
taxi path. Symbology indicative of corrective action to be taken is
shown at 606.
FIG. 6 depicts a moment in time when the aircraft 100 is being
driven by the electric taxi system, and trend line 604 shows the
predicted aircraft path. In display 600, trend line 604 indicates a
predicted excursion, in which aircraft 100 travels in a reverse
operation, away from the centerline of the taxi path, in reverse
and to the left, crosses onto the shoulder within an unsafe
distance, and continues to travel off taxi path 503 to the left.
The guidance and display system may generate an audible alert in
response to the predicted excursion. In response to the predicted
excursion, the guidance and display system graphically displays an
alert. The graphical display of the alert may comprise one or more
symbolic representations, such as: the trend line 604 rendered in a
visually distinguishable or highlighted manner that is easy to
detect and recognize; text and symbols 606 conveying corrective
action to avert the excursion, rendered in a visually
distinguishable or highlighted manner; etc.
FIG. 7 is a graphical representation of a display 500 having
rendered thereon a synthetic vision system map of an airport field
702 and aircraft 100. The display 700 includes a graphical
representation of a taxi path 703, which corresponds to the taxiway
on which the host aircraft 100 is currently traveling in a ground
operation. Graphical representations of various other features,
structures, fixtures, and/or elements associated with the airport
field 702 are included in display 700; such as other taxiways 708,
conformally rendered in accordance with their real-world
counterpart taxiways. Display 700 also includes a trend line 704
depicting the predicted aircraft taxi path. Symbology indicative of
corrective action to be taken is shown at 706.
FIG. 7 depicts a moment in time when the aircraft 100 is being
driven by the electric taxi system, and trend line 704 shows the
predicted aircraft path. In display 700, trend line 704 indicates a
predicted excursion, in which aircraft 100, making a right turn,
travels away from the centerline of the taxi path to the right,
crosses onto the shoulder within an unsafe distance, and continues
to travel off of taxi path 703 to the right. In the scenario of
FIG. 7, the aircraft steering setting is not at the maximum;
consequently, the corrective action is additional turning. The
guidance and display system may generate an audible alert in
response to the predicted excursion. In response to the predicted
excursion, the guidance and display system graphically displays an
alert. The graphical display of the alert may comprise one or more
symbolic representations, such as: the trend line 704 rendered in a
visually distinguishable or highlighted manner that is easy to
detect and recognize; text and symbols 706 conveying corrective
action to avert the excursion, rendered in a visually
distinguishable or highlighted manner; etc.
FIG. 8 is a graphical representation of a display 800 having
rendered thereon a synthetic vision system map of an airport field
802 and aircraft 100. The display 800 includes a graphical
representation of a taxi path 803, which corresponds to the taxiway
on which the host aircraft 100 is currently traveling in a ground
operation. Graphical representations of various other features,
structures, fixtures, and/or elements associated with the airport
field 802 are included in display 800; such as other taxiways 808,
810, 812, conformally rendered in accordance with their real-world
counterpart taxiways. Display 800 also includes a trend line 804
depicting the predicted aircraft taxi path. Symbology indicative of
corrective action to be taken is shown at 806.
FIG. 8 depicts a moment in time when the aircraft 100 is being
driven by the electric taxi system, and trend line 804 shows the
predicted aircraft path. In display 800, trend line 804 indicates a
predicted excursion, in which aircraft 100, making a tight right
turn, travels away from the centerline of the taxi path to the
right, crosses onto the shoulder within an unsafe distance, and
continues to travel off of taxi path 803 to the right. In the
scenario of FIG. 8, the aircraft steering setting is already at
maximum; consequently, the corrective action is to abort the turn.
The guidance and display system may generate an audible alert in
response to the predicted excursion. In response to the predicted
excursion, the guidance and display system graphically displays an
alert. The graphical display of the alert may comprise one or more
symbolic representations, such as: the trend line 804 rendered in a
visually distinguishable or highlighted manner that is easy to
detect and recognize; text and symbols 806 conveying corrective
action to avert the excursion, rendered in a visually
distinguishable or highlighted manner; etc.
Thus, there has been provided an aircraft taxi path guidance and
display system that graphically displays an alert and corrective
action when a deviation from the airport active surface area is
predicted.
While at least one exemplary embodiment has been presented in the
foregoing detailed description, it should be appreciated that a
vast number of variations exist. For example, the techniques and
methodologies presented here could also be deployed as part of a
fully automated guidance and display system to allow the flight
crew to monitor and visualize the execution of automated maneuvers.
It should also be appreciated that the exemplary embodiment or
embodiments described herein are not intended to limit the scope,
applicability, or configuration of the claimed subject matter in
any way. Rather, the foregoing detailed description will provide
those skilled in the art with a convenient road map for
implementing the described embodiment or embodiments. It should be
understood that various changes can be made in the function and
arrangement of elements without departing from the scope defined by
the claims, which includes known equivalents and foreseeable
equivalents at the time of filing this patent application.
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